Dryness/wetness responsive sensor having first and second wires spaced 5 nm to less than 20 μm apart

Abstract

A dryness/wetness responsive sensor having decreased size, and improved sensitivity and responsiveness. The present invention comprises a thin wire of a first metal and a thin wire of a second metal, which is different from the first metal, wherein the thin wires run in juxtaposition with each other on an insulating substrate, and wherein the spacing between the first thin wire and the second thin wire is in the range of 5 nm or more and less than 20 μm.

The invention claimed is: 
     
       1. A dryness/wetness responsive sensor comprising
 a thin wire of a first metal, 
 a thin wire of a second metal, the second metal being different from the first metal,
 wherein the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other on an insulating substrate, and 
 wherein a spacing between the first thin wire and the second thin wire is in a range of 5 nm or more and less than 20 μm, 
 
 a current measurement means electrically connected to the thin wire of the first metal and the thin wire of the second metal, and 
 an insulating protection film covering an area in which the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other,
 wherein the insulating protection film has a groove-shaped opening that exposes at least a part of the thin wires. 
 
 
     
     
       2. The dryness/wetness responsive sensor according to  claim 1 , wherein the groove-shape opening further exposes at least a part of a gap between the thin wire of the first metal and the thin wire of the second metal. 
     
     
       3. The dryness/wetness responsive sensor according to  claim 1 ,
 comprising a plurality of at least one selected from the group consisting of the thin wire of the first metal and the thin wire of the second metal, 
 wherein the thin wire of the first metal extends from a first side towards a second side that is opposite to the first side and the thin wire of the second metal extends from the second side towards the first side such that the thin wire of the first metal and the thin wire of the second metal run in parallel. 
 
     
     
       4. The dryness/wetness responsive sensor according to  claim 1 , wherein the thin wire of the first metal and the thin wire of the second metal are arranged in a double spiral. 
     
     
       5. The dryness/wetness responsive sensor according to  claim 1 , wherein the insulating substrate is a silicon substrate with a silicon oxide film on its surface. 
     
     
       6. The dryness/wetness responsive sensor according to  claim 1 , wherein the first metal is selected from a group consisting of gold, platinum, silver, titanium, an alloy thereof, and carbon. 
     
     
       7. The dryness/wetness responsive sensor according to  claim 1 , wherein the second metal is selected from a group consisting of silver, copper, iron, zinc, nickel, cobalt, aluminum, tin, chromium, molybdenum, manganese, magnesium, and an alloy thereof. 
     
     
       8. The dryness/wetness responsive sensor according to  claim 1 , wherein a number of pairs of the thin wire of the first metal and the thin wire of the second metal is more than 50. 
     
     
       9. The dryness/wetness responsive sensor according to  claim 1 , further comprising a meshed member covering an area in which the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other. 
     
     
       10. A dryness/wetness responsive sensor assembly for remote installation comprising the dryness/wetness responsive sensor according to  claim 1  attached to an attachment member having an attachment portion at one end for attachment to an object such that the dryness/wetness responsive sensor is attached to the object via the attachment member. 
     
     
       11. A dryness/wetness responsive sensor comprising
 a thin wire of a first metal, 
 a thin wire of a second metal, the second metal being different from the first metal, and 
 a current measurement means electrically connected to the thin wire of the first metal and the thin wire of the second metal, 
 wherein the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other on an insulating substrate, 
 wherein a spacing between the first thin wire and the second thin wire is in a range of 5 nm or more and less than 20 μm, and 
 wherein the insulating substrate comprises an opening portion passing through from one side to an opposite side of the insulating substrate, and the opening portion is obtained by removing at least a part of the insulating substrate corresponding to the spacing between the thin wire of the first metal and the thin wire of the second metal. 
 
     
     
       12. The dryness/wetness responsive sensor according to  claim 11 ,
 comprising a plurality of at least one selected from the group consisting of the thin wire of the first metal and the thin wire of the second metal, 
 wherein the thin wire of the first metal extends from a first side towards a second side that is opposite to the first side and the thin wire of the second metal extends from the second side towards the first side such that the thin wire of the first metal and the thin wire of the second metal run in parallel. 
 
     
     
       13. The dryness/wetness responsive sensor according to  claim 11 , wherein the thin wire of the first metal and the thin wire of the second metal are arranged in a double spiral. 
     
     
       14. The dryness/wetness responsive sensor according to  claim 11 , wherein the insulating substrate is a silicon substrate with a silicon oxide film on its surface. 
     
     
       15. The dryness/wetness responsive sensor according to  claim 11 , wherein the first metal is selected from a group consisting of gold, platinum, silver, titanium, an alloy thereof, and carbon. 
     
     
       16. The dryness/wetness responsive sensor according to  claim 11 , wherein the second metal is selected from a group consisting of silver, copper, iron, zinc, nickel, cobalt, aluminum, tin, chromium, molybdenum, manganese, magnesium, and an alloy thereof. 
     
     
       17. The dryness/wetness responsive sensor according to  claim 11 , wherein a number of pairs of the thin wire of the first metal and the thin wire of the second metal is more than 50. 
     
     
       18. The dryness/wetness responsive sensor according to  claim 11 , further comprising a meshed member covering an area in which the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other. 
     
     
       19. A dryness/wetness responsive sensor assembly for remote installation comprising the dryness/wetness responsive sensor according to  claim 11  attached to an attachment member having an attachment portion at one end for attachment to an object such that the dryness/wetness responsive sensor is attached to the object via the attachment member.